The objective of this study is to test and determine whether a high protein diet is efficacious, safe and beneficial to curtail food intake and body weight in obese adult human patients and to establish whether neurohormonal mechanisms of a high protein diet induce an early signal of fullness or satiety in a relevant experimental model, focusing on activation of gastric vagal afferents.

The primary endpoint is change in body weight, which is calculated as the difference between Day 1 (baseline) and 12 months. The primary objective is to compare the weight loss between each of the two high-protein diets and the standard diet. [ Time Frame: The primary outcome of weight loss is measured at the Baseline at Day 1, and at the end of the 12 months study period for each subject. ] [ Designated as safety issue: No ]

Safety variables: incidence, severity and duration of adverse events, vital signs, concomitant medications and physical examination results. [ Time Frame: Safety variables are measured at the time any adverse events occur, and vital signs, concomitant medications and physical examination results are measured at Baseline on Day 1 and monthly throughout the 12 month study period for each subject. ] [ Designated as safety issue: Yes ]

For inclusion in the study, patients must fulfill all of the following criteria:

Subjects must be a veteran.

Subjects must sign the VA Greater Los Angeles Healthcare System Institutional Review Board approved written informed consent prior to the initiation of any study-related activities or study specific procedures or randomization.

Subjects must have given written authorization for the release of protected health information in compliance with Health Insurance Portability and Accountability Act (HIPAA) regulations.

After the Informed Consent process, these additional Inclusion Criteria will be applied to potential subjects:

Age 21 years and older at screening.

BMI of 27 to 45 kg/m2 inclusive.

Subjects must be in good health as determined by medical history, physical examination performed by the Investigator (Study doctor) at the Screening stage, and screening clinical laboratory tests including chemistry panel and CBC.

Must have stable smoking habits (or be non-smokers) for at least 6 months prior to screening and agree not to intend to change such habits during the course of the study.

Subjects requiring the regular use of any prescription medication may be admitted to the study, providing the dose is stable.

Subjects must be able to communicate and cooperate with the Principal Investigator and the staff and willing to comply with the study instructions.

Any subject who has been on a very low calorie diet (less than 800 kcal/day) for a period of 4 months or more in the 12 months prior to screening, or who has lost greater than 10 kg in the 6 months prior to screening.

Any subject who has a history of diabetic gastroparesis or gastric emptying disorder as indicated in the potential subject's medical history and VA's Computer Patient Record System (CPRS).

Use of any other investigational drug(s) within 8 weeks prior to screening.

TSH outside of normal range disorder, as indicated in the potential subject's medical history, the VA's Computer Patient Record System (CPRS) and laboratory tests performed during the screening process.

Subjects who drink more than 1 alcoholic beverage per day (that is: 1 beer; or 1 glass of wine; or 1 shot of liquor).

Pregnant women or women likely to become pregnant during the course of the study may not participate in this study. Female subjects must not be able to conceive by reason of surgery, radiation, one year past the onset of menopause, or an approved method of contraception.

No vulnerable subjects will be included in the study.

Contacts and Locations

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study.
To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below.
For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01146704